Block-signal system.



L. BLOCK SIGNAL SYSTEM. APMEGATEGN HLM) AUG. '1, w09.

Eatented Juy 7, E914.

5 SHEETSSHEE-T 2.

INYE'NTUR EAI/HEMEL MN5 L, A. Hmmm,

BLOCK SIGNAL SYSTEM. APPLICTON FH;

ED AUGHI, N09` L. A. HAWKINS,

BLOCK SIGNAL SYSTEM.

APPLIUATNN FILED m0,?. ww

1,102,917. Patented July T, 1914:

SHEETS l nm N #g2- m u Figa. z5

CJi

UUTEB STA'..

TECH PENNSYLVANE.-

cation of the system disoiose in a compamon application, Seiiai No. 511,653, August 1969. in af-ppiicetion dis-- dosed e. system in Whisk the signais ae a1'- i'nnger to gif-fe danger, caution anni cien? in- Cxioations, e* i by: Vtv.'@position or oy one tziieeposiinn erm, emi in, Mnien the oonro o* sig-'nais is obtained 1 wires o an arrangement comprising a pair of ti on: ieiaje fo? oioc' convoiiing the caution and ci inicetions, respeotiveiy, eeeii having two ooperatinjg windinge3 one connected to the tradi and t'ne other supplied with alternating Climent in dependentiy of the tinck circuits, the enfi'ens. the imiter windings of the two rei/55 of each nai? being diierent charac-tei: and pzefei'aiiy of ieient phase, with. ineens conti'oied by e twin in one biock for changthe character of the track Current in the piceingg'kid, prefeznoi by snif ngz its A er; to eneigze iist one sind then 'phage both oi the imeir lays of the Wemding Mock. piinoipni advantages of that svstezn, as oompa with oixnei Wueiees tenis, nie, ytint track relays oi the moet eiiicient type 12 empoyed, so that the ouxient consumption is reduced to n minimum; second, since the relay controiiing the Caution indication is not even momentniiiy nergizod when the phase ot :the track @meent is :shifted 'to energize the rainy controlling the dem: indication, it is unnecessary eo employ a quiclvnctirig switch for controlling' the phase oi the track current; and third, iE the transformers ot adjacent biof-.ie are ievoiseiy connected the breaking down f the insulated joints between two adjacent block sections xviii aiways cause the relays adjacent io tin-se ointe to open their Contact so that the signal controiied by them will be put at stop; thus, fais@ dem' indica- Speeication ci' Letten etfssaii.

i caution oehinti it.

iii

tione poseibie in othe es: ejsioms are impossible in this SYStem.

My present invention aonsists in an exten sion of the Sjseten oi .my companion nppiication for the nupose of obtaining; :in overlap; that is, oi plm'ng nne' h@ contzoi off te train thiee signnis behind it, so that the tiain may two signale :it 'lion one at soutien ont too anf two at To to en', means oontroiief by 'ti' movements, for s1'ftiiig' the pinne oi track surfent to time@ different positions and pmi' raak relays ieeponsive to vaifiaiions se the truck Cuire responsivein tnie it innen* con-.ihk ons to the tinee iieiient 'phases of the trank suivent.

Mt' in venti vest be undei'stood by io ne :ieeeinnnying i'nwings, in

7 and 8 .n's the movin@ parts eieys; .3 shows a inodiiioation of the ni; Figs. 10, 11, il?

nis expianatoiy oi' Fig, M shows :i

and 13 ae vector diag, the modification of i* i., *fui-tfno? inodiiicniion the ,'stein, in which the number of track i'eaj" s reduceci; if l5 to 18 are vector fiiagrams expnnatory of Fig, 14; ,if-'igt l0 shows :i mociiieation of the arrangement ot f empiop'ing cutie@- tions :uingeti to gli on @veria i o? ini e bloei F to are vento? (i agi'ann-a nlanutory of Figi. 19; Fig. shows n iuither modification of the a-ziringemont of Fig. 14 :ii-ranged to give an evening of a compiete block, @mi 2G to '28 are Vector diagrams exp? natorjg; of Fig. 25,

In Fig. L to if represent the track circuits of the bocks soparnte from each other in insuated liointe have indioated oner of the oiooks as sub-di ideal, that is, composed o two cnt-sections A. and A2, oni?.7 single tinck circ-uit being' shown for each of the remaining mocks. E represents a threepimee generator im' supplying i11- ternating current 'fof the signai circuits through the transmission wires ,7). C to C iepl'eeent transformers having their primar 'I i i ries connected to' thelseveral phases of the These transformers have 'their primaries ,wf-connected so as to give twophase voltages on their secondaries, in other words, they are connected in the well-known three-phase, two-phasemanner.

c c represent impedances'n circuit with the secondaries of these transformers. E to E4 represont small traclrtransformer's, the primaries of whichare supplied from the main transformers throu h tire impedances c c and the sccondarieso which are connected tothe Vtraclr circuits. The impedances prevent the main transformers from being short circuited when the track transformers are shortcircnited by trains and also when the tracktransformers are being vswitched from one mainv transformer to another. D `to D14 represent track relays of which three are shown for each traclr circuit. These relays are indicated diagrammatic-ally as of the well-known induction type, each'comprising a short-circuited member Z actuating the re- 'lay contacts, a winding ci connected to the track and a second cooperating `Winding Z1 supplied with alternating current independently of the track circuit directly from the secondaries of the main transformers C to C?. F to F3 represent signals for the blocks, which are arranged to give the three indications of danger, caution and clear. i

In the drawings are shown diagrammath cally one-arm three-position signals, but it will be understood that my invention is equally applicable to signals of any type or arrangement adapted to give the three said indications. The signal mechanisms are not shown in order. to avoid complicating the drawings.

rllhc movement of the signals from stop to caution taires place upon the closing of the -contacts of the relays D, D, D9 and D11, while the movementof the signals from caution to clear takes place upon the closing of the contacts of the relays DI, D?, D10, and D13. it will be understood that the conductor leading to the lower side of the blade is the common return and that the circuit controlling the n'iojvement from stop to cau` tion is that which extends from the'upper side of the blade directly to the'contacts of relay D, D", etc., while that controlling the movement from caution to clear comprises the conductor extending from the upper side of the blade directly to the contacts of relay D", D7, etc. f represents a movable contact cr sector, mounted on the signal shaft or otherwise operated by the signal, provided with tour stationary contact members f to ft The connection between Contact fand the signal is indicated diagrammatically by a dotted line. This contact in conjunction with relays D2, Ds, D11 and'D` controls the connections of the track transformers E, E?,

E3, E* to the sccondaries of' the main trans-f formers, and thereby controls they phase of the track current. t will be noted that the windings d2 of the three relays for each track circuit are supplied with currentsof' ditlerent phase. The winding d2 of relay D, Jfor instance, is connected across the secondary of transformer@ while the correing winding of relay D has an intermediate position.

The operation of the system is as ollows: Nith a train in track section A5 the track windings of the three relays D1, D13 and D14 are short-circuited, so that all. three relays open their front contacts and signal F3 stands at danger or stop position. `The conditions in the windings d2 of the three relays are as indicated in the vector diagram of Fig. 2, in which o o represents the 'volt-A age impressed on the Winding (Z2 of relay D12 and 0 c" the current in that winding which lags behind the voltage by a considerable angle. Similarly, the voltage and current of winding (Z2 of relay D13 are indicated by 0 o2 and o i2, respectively, and in winding d1 of relay D1* by 0 o3 ando 3. Since the relay D14 has its front contacts open and its back contact closed the circuit of the primary of track transformer E* extends from the left-hand terminal ofthe primary winding through contacts f3, f and f', back contacts of relay D14, to the right-hand terminal of the secondary of main transformer C9, through half thc winding oii this transformer and from the central tap through the impedance c to the right-hand terminal of the primary of transformer Et. The pri mary of the track transformer is thus con- 1 may be represented by 0 c' in Fig. 3 lagging y by a comparatively small angle behind the voltage 0 o3. lf the circuits are properlyarranged the angle t' 0 is may be made approximately 45. lf it is desired to use inductive impedances. the desired phase relation may be obtained by impressing the proper voltages on the windings d2 of the relays, and sincetwo-phase voltages from Avthe secondaries of the transformers Cs andfCD me available 'plv "est of ille veiling-ee im- 3 ii will lie seen that ille torque in relay D3 pressed on 'tlzeee #indulge-'nf the relays 11' j 1s' lw Slime as m i'elnv D, since the eine 0i umile amymzig #leal/fell, f Li the salme :is the .eine el 30. Comwinding nl' Velay l" :mi bellied the equal levez-se turque in bella relays eine@ ili ,current in tlm zut-r'respfummw of eine 45C ,is ilse mine :is ille sin;l mi i350. 75

hrw l :uxfl D lily will pecllveljf. @luy D" has. Umsequemly, clnaml it con' li' the relays :are so wrmwl mi' fumier-real iliat 'in-hie. nml thi# flws'ee ille vi: tit eeniwlllng 'when tlle cum'vni in tlm i'zifl: winding leads die inn-cement (if Signal 1" lrmi sop to the uvrent lx1 ille other Winding a mique is. Quellen. While the sive-,fl milliers tlxiH moveprmluliwl tmfling le. close lli# 'iront -rfmil'zicis menig llw cemact j leaves until-:fl f 80 of llxe relay, then ivlzw lill' v-:ill lmve such a :mzl ilien engages Crmtzirt f". Cuntmt in' `lue Wlsile relays :mil lll will lieve e through ille lli-wl( fonlneis nli i'eln'v l!" :ml reversi-lfn'fue. Relay l ima.consequently, uninet j" (llrwily. :im venne/@tell im el rlfml ih. lr'ml Mmmm-l5 :mil mene-:l li. imfli 1m l. *e4-mimi ille sevmwlny el mms- -nlif'azlefl. lil flfiizlgsu il lmsnotlui-mw (f5. eu tival'. if? what? airain en- :w1-#1l tl inurl: Cil'- i-iml the lllwli3 wie? D" (fla'is'fwl its lmcl; :x1' f1'f'lm\1fe:l, eminem lwlfm'e Signal F" had movi-rl lm ll in step wetifm :mfl if Contact f could ein' L? wenn@ e5 for@ ille Emiel( mnfnrfls :m: opviiwl. Dm'A ln' lllis reason Contacts d7" 21ml are :un ing' ille time limi lmili fwul :zml heck cfm ranged so limi. one opens befme the oi'hei zz f' :we (flwseil ille sefomlluy nf lmixsf-lnss as imlic'ate'l in imlecl lines` mi signal Tnm' l le im pnl-lille! will, line Y if {ffnuet f* lmwevei engaged before zim-lwi'znel' f. el ilm the engem 1n eonmfl is dlscngzigerl from commit f. At 95 Y lq fi'f'uii if" during; ilzls -ime is ille reellis time the left-hand liall" of the Secondary :mi nl' llav, um .nt of -lilleee iwf) tiene! di' ii-e nsfoi'me' C5 is cenneeted in parallel 'pien :mfl consegue advanced in phase with the Secondary of transformer C4. This bv 'f. again advances ille phase of ille track cuir a Si ull will lw ,Semi by wnfiflering the Yeni nf track circuit i2 450, and theigwlien 100 mi' wlmmflng the mix-reni o in Fig. 3 by lu criminel. 'f leaves Contact f2, tiansfoi'mer C4 film? tlm fmljv' i ills# efe lo iiei'eeSe Semedisconnected from transforniei'E2 and the wlmi', 'iie tmq in Velay D8 em'respeirling phase of the current in reck circuit A2 luis in relay D, n-ge the enfrente in 'che iw 'new been advanced 90@ Without iriel'uptl 'b windings; me than disilfi :ed :femm each other ing its Flow. Condizione in relays D3, D* lO- lry :1ppwxlmnteljf S500 inaueafl si" by only @of und D aye then as iiiflieeied by the vector und. if) deber-ey the feierte torque in relay E@ diagram of Fig. Compeing this ligure fcerieepfiiifling i@ relu" DQ, since tlie cui'ens Willi Fig. e it Will ive that the raeii We Winding im lien in. 'plies-e. luis current 0 a' has "eeen eilif'imeefl 9Go. @Jom- Cm il skill limveer, be heli in openl paring relay "DE with eley Us it will be seen 1l@ p tim; lijf gravity. Baleine; iliis tha. ilie -rael cu'ien new lage lc behind n, sume Cuvent firms through the seemiflthe C'uenl; 0 2'. instead of leecliixg it by lia m" iii-:an 'formera C and C7 in series, angle, se illetthe torque in relay D le e reli'nleal in ammini since it must Verse torque sind the relay line openevl its liimpii lmgli impe-fleuves: n in As contacts. Assuming for a moment lmt relay E eempleiee ith' mmf-ment und @pene there is a signal at relays D3: D* and D5 and its baal: ccmziee, tz'nusformei" C :alone is that the signal circuits are Connected :is muerte-'l te lle primmfy' 0i truck ians- Sliewn for signal F, it will be seen that ille former E". lie circuit @vending through opening :mi the 'from Contacts of relay D5 Contacts f3." if, f2 :mil from comme of relay would have im eleclJ on the t'eek eurvent of 120 [lie plies@ of the our it m tradi eiziille next block, Since with lie Signal ai. @uit ilu* le;kwmswquently. di placed 9190 from wmiimi position tile eonneelimis to the priljlmli in imf'l fiivuit 5i* :zml the wmflili mary of lle aflr mes-forme? are mafle m relays D, EY :mil Dl may be'i'epresezxrerl life@ if: tli'rrmgli elle. nl mnlees inflev l. it, will be fawn from., lils'igme ieiflenily of the efmiacs e? relay DS. COm- 12" l'lw l'nfk emx'mit o lvzifls ille emem glaring rela?! l 3 Wili relay D iiy will lie Seen ,am ii'imlim 'Z2 ei' relays D8 :imi il lmtilwtinel enfrenta/lewis theemrentoi A0. respectively, While il lugs velay by i350 insiemi of by :is in l eiiieni in ille winding d2 el relay DG smrl the inrques ef relai/S B3 and `20milaring- Ll i aienily,tl1e same. Cumparizg is@ Uil.

gz y 1,102,917

relay D with relay D7 it will be seen that the track current leads the current o 'i12 by 45 in relay D4 instead of lagging behind it by that angle as in relay D. The torque of relay D* tends to close the relay contacts and if there werea signal at this relay connected vas shown for signal E the signal would be moved from caution to clear position. In order to illustrate the application of' the system to a cut-section. nosignal is 4 shown at these relays, the contacts of which are arranged. to control the circuit of the primary of track transformer Evof track circuit A. were in section A2, so that all three relays D3, D* and D5 were denergized, the primaryI circuit of transformer E would beI opened, relays D, D and D2 would be deenergized, and signal F would stand at stop position. With a train in section A3 the conditions of relays D5, D* and D would be the same as that shown for relays D", D10. and D in Fig. 3, that is, relay D5 would be energized and relays D3 and D* would bedenergized'. Under these conditions the left-hand primary terminal of track transformerE would be connected through the back contact of relay l)3 and front contacts of relay D5 to the right-hand secondary terminal of transformer C3. In other Words, vtrack transformer E would then be connected precisely as shown for track transi former Et, the conditions of relays D, D

and D2 would be the same as the condition of the relays for track section A* as shown in the ligure, and the signal F would still remain at stop; in other words, a train in sectionlA,3 holds signal F at stop and, consequently, the signal next in'the rear at caution.

When a train is in section A* the condition of relays D3, D4 and D5 will be as shown in Fig. 4 for relays D, D7 and D3; that is, re-4 lays D3 and D would be energized while relay Dt would be denergized. The lefthand primary terminal of transformer E is new connected through the front contacts of relay' D3 and the back contacts of relay D4 to transformer C2 so that transformer E would be connected precisely as transformer E is shown connected. Consequently, the condition of relays D, D and D2 would under these conditions be the same as shown for relays D,'D7 and Ds and the signal F would, consequently, moveto caution. The contacts of relay/.D3 are made flexible in the manner before described, so as to close the front contacta before opening the back and thereby to shift the phase of the current in track circuit A Without interrupting its flow. With a train in block A the relays D3 and D are energized as already de scribed, while relay D5 is denergized. The

left-hand primary 'terminal of transformer E is nowfconnected through the front con It will be seen that if a train" tacts of relays Ds and D* to the left-hand secondary terminal of transformer C, so that transformer E is now connected 'exactly like transformer E2. Consequently, the condition of relays D, D and D2 is the same as that of relays D, D* and 'D5 and is as shown by the vector diagram of Fig. 6. The signal F has, consequently, moved from caution to clear position as shown. During this movement no change in circuit connec-l tions is produced by the contact f, so that the conditions in the track circuit. A have not been altered. It will thus be-seen that by arranging the contacts of the track relays of cut-sections to establish the same connections under the same conditions as are established by the contacts on the signal shaft, the control may .be carried back through. as

many cut-sections as desired without interfering with the operation of the system.

The reason that the three leads are taken from the secondaries of transformers C', C3, C, etc., is simply to provide' a convenient means for deriving from this transformer two voltages displaced in 'phase from each other by 180, that is, to obtain the conditions shown in Fig. 3 on one'hand and in Fig. 6 on the other, witha simple arrange- I ment of wiring and contacts.

It will be seen that the connections of track transformers of adjacent track sections are relatively reversed and also that the connections of relays of adjacent track circuits are relatively reversed. Since the track relays are reversed 1n the same track circuits 1n which the track transformers are re` 'versed, this reversal has not heretofore been mentioned, since so far as the operation of each block considered by itself is concerned this double reversal is of no effect. It be` comes of importance, however, in the case of leakage of current from one track section to the next, due to the breaking down of insulated joints, or from any other cause. In such a case the current that leaks to the relays is in a direction opposite to that which the same current has upon the relays of its own track circuit, so that no false clear indication can be obtained because of this leakage. The precise effect of such leakage curthe three relays, under different conditions corresponding to different ositions of the signal controlled by these re ays, will be ob-v vious from va consideration of the vector diagrams and need not be described inv detail. It will be noted that under some conditions broken down joints between track secrent through broken down joints on each of v i weeen wiiiings d2 'of reiejfsi 3E. eed D2.; er A932 emi D51. etc.. 'are retetiveiy reversed, es iiidieeed in Eig. l@ se eemeref with Fig. 2, e e1" in ail ligures insieeteig the. veitege izpreeeeci en winding ei tive ree eentreiing the eriginel movement imm step 'te camion, that is, El. E331. .U23 eee., whie e e3 seats the voltage for 23"., B51. ete.. The conneetiene of the sentirete of reiee Dil, E51, etc., ere some-What ieiiei Witt best be unersteeii by eeneidering the emiditiens in the zerera Meeks eeeem. a train in section tiie e 1, 'Qml :and

zing sie track 'n'.ieeted Fig. 10; the sigiie Fa cenee-.uemy Stands et m3?,

hetreck stemmer E3 has itsiprimery connected'through eenteete f2, f. and im pedanee l; u the git fr '3 "lr-enriiry termi nui et transiiii'n i C :ae that ne piese of the current in truck circuit is es indicated by' o in Fig. li which shows the con diiifms in relays D2, D1 anfl i551. Wilt be seen in this diagram that i'eej/ B41 is energized white relays D?! :in-:i DB1 have reverse tei-ques. Signal if is.. eensequeiitiy, moved from elem' in aanzien positien and transmmer C* is' ennzweted te the iet-han termina?, of unf-i: crmisermer E: through remmers f2, if', f3. impedance c, beek Contactv of-reav DTA te the secondary o transformer C". The trtif'lr euri-entita track circuit A2 is, eensequenty, advancefi J .with respect to track cireii, -X3 :ind the cenfiitie-ns in reiejv D21, d1 and D5. are es indicated in l2. t will be seen from this figure that reiays D31 and D5, are both energized so that signal F remains at cautionT While relay D51 has shifted the connection of the left-hand terminali of treck transformer E from transformer C: to the left-hand terminal of transfminer C3. Relay D cios'e its front eentaets before Opening' its: beek contacts. se that the current 5er: in traer circuit is not interrupted, but is advaneed by 90: as represented o 2', in Fig. it will be seen from this igue. 'which shows the Conditions in.reizi vs D1. D', and i??? that relays D'l an?y D3, are energized While reiey DX is deenergized. The deinergiviaion nf relay D1 hasnei; aectef F since its contactsY have been @hunted by the upper front eoni The transformer E2 being tacts of reiay D21, whie the closing of the contacts o relay D'l nas caused the signal te meve from caution to cie-nr. During this movement the Contact j eee mede no change 331 the eireuit eonneeti ns o transformer E, so that the imei; Section iiiee not been in f ige. i and 9 three reiaye 'per track seetien have been empieyeci for obtaining the three dierent eorihinaiene corresponding *te the three et" the track eur-rent. t will "ne seen, hen/ever. that three di'erent lays; that is, with each of die me relatifs energized singly end beth of the relays en ergizeei sininiteneeusiy. Such e modification is shown in Fig. le in which relays D2, D, BS, ete.. of Fig. E. are erniftefl ani. rea/e 92 anni D?. ete., ceased te perform the et emitteei reiays. The riz-mamctiee relays are ineieeled in E i Si., D32, D52 emi E72. Reieys L2, D22., Die smeT-L rresperite reeys D, and i3# ete., ef l. The *a/,ieinge of reiejys Dez, and DT., ef Fi?. 14 ere eeetroied by trie eeriteete jfi en the signet shst in suc'e e. manner tiret the 'current the reiay Winding is reversed et certain timesq se as to cause it at one time to resi-.semi te current ef e certain phase ami at enetiier time te current ci another p use The operatien ef this modification Wii best be undereevera truck sections shown. With a train in section A4, as shown. beth reiays E2, D72 are deuei'gized and the signa Fa stands at stop. The conditions in winding 2 of the ieiays are shown in Fig. l5 in which 0 v and o i reiste to relay '92. The winding d2 of feisty D12 is onnected through contacts f, f and to the right-hand .secendery terminai of transformer C7. YWith this connection tixis relnv coirespomis in its operation to relay E of Fig. l. The left-hand primary teiminai efvtrunstm'mer E is een-v neeted through contacts lf2. fami f', back contacts of relay D72 and impedance c te the right henri teimina'l of the seeendary of trunsffn'mer C7. Transformer 'E3 is thus eenneetefi the seme as transformer E4 in Fig. l and the (renditions in rei frs D42 and D5., are as represented by Fig. 1G. it wiii 'ne seeggefrnm this figure that (miv reim' D52 has e torque tending to eiose ite' cont-Arts While reim' D4.: is denersrizaed. Signal F2? cfenseqneeti. remains fit finger but The new neetions for ne left-henri terminal of transformer F? "here been transferred frem trans former CF te transfernier C* by the dosing of the front contacts of the relay1 D52 and not effected the Signai F2 since they are onen--eireuited et the contacts-0f relay U2. connected to 'the conditions can ee ebtaiine 'with ont); two re steed by censidering the eonitione in the transformer C* the current in track circuit A3 is advanced 90 with respect to the current in 'track circuit A3. l By considering Fig. lvshoiving the conditions in track A it will be seen that the Erst eiect of advancing the current 0 i Would be to energize relay D42 Without denergizing relay D52, which would result in starting the movement of the signal from stop to caution position. in the course of this movement contact y iirst leaves contact f5 and then engages f7. This reverses the connection of the winding d2 of the relay and, consequently, produces the conditions at relays D22 and'ls2 shown in Fig. 17. Comparing this figure with Fig. 16 it will be seen first that relay D22 has a positive torque instead of a reverse torque, While, since the voltage and current in Winding d2 of relay D82, represented by o v2 and o 2, are reversed in phase as compared with Fig. 16, the relay D32 has been denergized through the reversal of its connections. Signal F', consequently, moves to caution position but stops there. During this inotion the contact f has shifted the connection yfrom the left-hand terminal of transformer E from transformer Cf" to the left-hand terminal of the secondary of transformer C8. This connection has beeiiestablished through Contact 3 before Contact finger f5 was opencircuite as indicated in dotted lines at signal F3 and consequently, before relay D82 was denergized, so that the current loiv in trackcii'cuit A Was not interrupted. The conditionsin relays D2 and D2 are now as represented bv Fig. 18, from which it will be seen that both relays D2 and D', are enerv gized vand the signal F has nioved to clear position. During this movement the contacts f and f* make no further change in the circuit connections.

Fig. 19 shows a modification .of Fig. 14

adapted for use Where ciitsections are ein@ ployed and Where an overlap o less than a complete block is required. This figure shows two cut-sections per block with an overlap of one cut section or half a block. The connections of the relay windings are the same as in Fig. 1s but the contact conu nections are somewhat altered. train in section A5 relays Dit, and D, are deenergized, the conditions in these relays be` ing as shown in Fig. 20. The primary yof transformer E4 is open-circiiited at the lower front contacts of relay D93 so that relays D?,V

and B73 are also open-circuited. The voltages and currents or' the vwindings d2 of these relays are as shown in Fig. 2l. The left-hand primary terminal of transformer E3 is connected through the back contacts of relay D63 to the right-hand terminal oi transformer C7, s o that the conditions in re- .la s Da and D5, are as indicated in Fig. 22. 'Elie relay D53 is consequently energized connecting the letthand primary termin-ai of With a V@ Lineair Vtransformer E2 to traiisioriiier C* so that the conditions in relayslz3 and E, are its.;

indicated in Fig. 23. .Relay D23 is, consequently, energized While rela-y D33 is deenergized. Transformer E is connected through the :trent contacts of relegy D33 and back contacts if i il?, to transrormer C2,

so that the condi one in relays D3 'and DQ.' y'

behind it two signals at step 4and onev atA caution. -Vihen the train moves ont of section A to the next section beyond, the condition of relays D33 and D, becomes the saine as shoivn for relays D4, and D53. Consequently, Vthe conditions oi relays B43 and D53 becomes the vsame as shown for relays l)3 and DB, and the signal F moves `to caution position. Thischanges the connections of transf riner E2 from transformer CJl to transform i' C5, shifting the phase of the current in track sec-tion A? o so as to energize relay D33, which shifts the connec tion of transformer E trom transformer C2 to transformer C3, thereby energizing relay D', and clearing signal F. That is, With a train in the second or outgoing section of the block it has behind it one signal at stop and one at caution. ln other Words, the overlap obtained with Fig-19 is of one 'cut-section or half a block. The two relay arrangement may equally Well be arranged to give e co, plete block overlap as shown in Fig. 25. In this figure `the windings of relays D. and D1 are connected the saine as those of rellays De and D43 in Fig. 19. Relays D@ and D54 are also connected as relays D3 and D58 are connected in Fig. 19. Relay'Dis connected the saine as Da in Fig. 19 but relay- D3, has its 'Winding controlled by relay D24, so that it is reversed Whenrelay D'4 is energized. or deneigized. This makes the coniiectioii and operation of' relay B3,x the saine as relays Dd and Ei. With a train in section A3' relaysltfand D, are denergized, the voltages' and currents in their windings being as shoivn'in Fig. 26. The left-hand 'terminal' of transformer `itz is connected Vthroiiglfi contacts f2, f, and back contacts of relay D54 to transformer C5 andthe con ditioiis in relays Beg-and B84 are as indicated by Fig. 27; Reiay D@ being denergiaed, the connection, of Winding d2 of relay Dsisfthe saine as that of relay D54, as is eeen by comparing AFigs. 25 and27. Relay E34, consequently, is energized and transformer E is connected through the baclreontacts of relay D24 and front contacts ot relay E?, to transformer AC3, so that transformer E bis connected lthe saine as trensoriner ES and conditions in relays D* CIJ ncl DQ are the seme as in relays D24 enel U2, es indicated bfxflig. QS. "When ilhe trein nieves ont :ri Secien {l} te the next seeion beyond lie ecniiiions with iwpect m veleni: D@ nucl Dfi; will 'become the :same am. tl emnliens of ielnys D.; and DQ would guarded by signal F the condiions et 'felays Dvand D1 become the same as Shown foi. relays ll and 'if/"Q Signal FQ conse quentl'y, ieifnains :JS step mit transforme? l?? is *ellen cennececl s lrensfermex' E is Shown conneete in the chewing; that is, te infine? C or C4. fhen lie tensfof'mei' E2 Elms connected the current is advanced 550 in eeeiion which, lijf an nepecien of Fig. 2? will be eeen vto have he effetti, of energizing relay D24 'Wh l1, after Clesing; ite 'from contacts, reverses 'the connections (if 'the Winding d2 of. relay D@4 which then becomes denex'gied` Under these condiione the cimnecten o? transformer E" exends through the fiont eoiees of .relay D@ enel beck commis ieley 32 e0 transformez' C?, se tha the phase of alle emmene in ismael; eil/- eine also advenee 9G". iis energizee ieley l and causes Signal l? te move iiom stop lo camion assieme, which by ils nievement reverses lili-e whirling '.2 S relay DQ and deneigizes that elay. This shifs alie connection of ransoi'mer E from tiene foi-)ner C to transforme? C again advancing The phase of the surreale in sectifm S C. The elieet of this avanee may 'be under- #mml by considering lie effect of reversing the phase of the cuz-Yeni, in wack 'secion Ai, it being i'emembeieel that relay D24 is elreedy energized and diet zelay D2 has its winding Z2 reversed from what is shown in Pif. 27.

lt -will be seen tlie under these conditions, :im Climent, o 'i ing zeveised from Wlia is flmn'n in 21 beth relays D24' and B31.: would be energized and traneformez E would ne connected through the from eentuffte ef the two relays in Series lo die lefimml secondary terminal O' ransformei C3. This would again advance the cnerent in inni: secion A nfl it will be seen from an inem-eilen of 28, remembering that o of i l fj have been ieversed, that a enii'f-n'ck njzllfieite in phase lo o i i Fig. :28, will enerfixe limn relays D4 and E"4 t@ (euse the Signal to move from caution te clear, dwing.

farming nien?, e; bleek 0i elle@ all bei: of iiael i e 'A 1 ,sleek may be ve? es desired., the ammini o Overlap U12-.lle any numbei' of i'ucl eexrztiens not el; Ceecling :i efinipleie ble-eli, and nnmei'ous clileren velay cnnieiiatifrne muy be een plcffec l, eliex'ei'm'e do not deeii'e to limitl lf to the particular eonneaci'eiie and af rangements; parte `Shown unil flesfribenl. M51 fi'flmngl; l have described :i system in which the enii'ent is unused to change its phase tu produce the desired Signal indicaions, it' will be nnclex'stond tha olaex modifie-sen of me current the?, invelvee a flietinc ehenge in cliazemei might be'employed, and aim in the appencleel claims lo cove? all znofiicaitions th/ginie Wi'nin the scape mi my invenon, wliei'ihe elle change. i-- lle character of lle @miem emf is a change in il "e er etlmzwise,

Gleim es new nel esire i@ secure xi bleek signal system., imei( eiicues foi fie bieclfe, sources; of 'eleinaii'n' cui, rem:- oi the 'neck circling ineens ccgfirelled lie three clnuzmtere of the track e'mren7 Seid" means inclmling'si plurality of taclf relays im' said tree-l: eieuits said {inet-named means including a like plumlity of relays in enel; of the bloei in advance the several ifeef enf; iiael eiicuit being differ- Qnil; e poneive io variations of chere-teiof the. eiecl current, 'for the blocks arranged indicate danger, camion and Clea, and cenml eiicuis fel" "fil signals eoni'ffll'enl by: die Sereni combinations ef @seele bv three Signa anni' n Y ons, one in one l pesitiens and tive in elle other.

U,- ln bleek signal eAvS-em, rael circiiis Ffm' 'elle blocks, seueee el alternating mieren?,

pei-mining; *to lie fcei'iesponeling blocks.-

^ behind e trein are lielfl plied .to atrack circuit to assume three dis? tinct characters successively as thetrain i passes-through-the blocks in advance, and a plurality of track relays for said track circuit each havinga Winding supplied with current from the track and a second coperating winding supplied with alternating current from a source aside from the track, the currents in saidse'cond winding diierin in character in the severalrelays for vsai track circuit.

4. In a block signallsystem` track circuits, -sources of polyphase alternating current for the track circuits, means controlled by a moving train for shifting the phase of the current'` supplied to la track circuit to three distingt positions, whereby said current has three different phases successively as the train passes through the blocks in advance,

and means responsive in three different ways to the three phases ofthe track current, said' means including a plurality of track relays for said track circuit, the several relays of said track circuit beingdiierently responsive to variations of phase of the track current.

5. In a block signal system, track circuits for the blocks, sources of poly-phase alternat ing current vfor the track circuits, means controlled by a moving train vfor shifting the phase of the current supplied to a track circuit to three distinct positions, whereby said current has' three different phases successively as the train passes through the blocks in advance, and means responsive in three diilcrent Ways to the three phases of the trackcurrent, said means including a plu-` rality of track relaysfor said track circuit, and said phase-shifting means including a like plurality of relays for each of the three blocksin advance, the several relays or any one track circuit being diierently re# sponsive to variations of phase of the trackI current, signals for' the blocks arranged to indicate danger, caution and clear, and control circuitsv for said signals controlled by the different combinations of track relays pertaining to the corresponding bloc-ks whereby three signals behind a train are held in danger and caution positions, one in one of said positions and two in the other.

6. ln a block signal' system, track circuits for vthe blocks, sources of polyphase alternating current for the track circuits, means controlled by a moving trainfor shifting the hase of the current supplied to a track circuit to three distinct positions,'whereby said current has three different phases successively as the train passes through the blocks in advance, and a plurality of track relays for said track circuit each having a Winding supplied with current from the track and a second coperating winding supplied with alternating. current from a source aside from the track, the currents in said second Awindings diilering in phase in the several relays for said track circuit.

7. In a block signal system, track circuits, sources of polyphase alternating current for the track circuits, means controlled by a moving train for shifting the phase ofthe current supplied to a track circuit to three distinct positions, whereby said current has three different phases successively as the train passes through the blocks in advance, a lplurality of track relays for said track circuitl each having a Winding supplied With current from'the track and a second coperating winding supplied with alternating current from a source aside from the track, the currents Ain said second windings diilfering in phase in the several relays for Ysaid track circuit, said phaselshifting means includin a like plurality of relays for each of the t ree blocks in advance, signals for the blocks arranged to indicate danger, caution, and clear, and control circuitsfor said signals controlled by the track relays pertaining to the corresponding blocks in one of said positions and tvvo in the other.

8. 'ln a block signal system, track circuits for the blocks, sources of polyphase alternating current for the track circuits, means phase ofthe current Asupplied to a track circuit to three distinct positions, whereby said current has three different phases .successively as the train passes through the blocks in advance, and means responsive in three dill'erent ways to the three phases of the track current, said means including a plurality of track relays for said track circuits, the several relays of said track circuit being diiierently responsive to variations of phase of the track current, said phase-shifting ofthe track current gradually Without interrupting its iiovv.

9. In a block signal system, track circuits for the blocks, sources of polyphase alternating current for the track circuits, means controlled by a moving train for shifting the phase of the current supplied to a track cir- 'c'uittopthree distinct positions, whereby said current 'has three diierent phases successively as the rtrain vpasses through the blocks in advance, and aplurality o track relays for said track circuit each having a winding supplied with 'currentV froml the track and a second coperating Winding supplied with alternating current from a source aside from the track, the currents in said second vWindings diilering in phase intlieseveral relays for said track lcircuit, said phase-shifting whereby threeU signals behind a train `are, held in danger and caution positions, one-V means being arranged to shift the phase` meansbeing arranged to shift the phase of controlled by a moving train for shifting the ne track currcnt graduaiiy Without inter# upting; its cw.

10Q n a blcckhsignni system, track cicuits im the blccks, sources of pciypimse @hermiing'cmrent fm' the track circuits, means controlled by a moving train im shifsiug the phase of ifnc current supiiied tc a 'track crcui to ,three distinct positions, whereby said curcn has three different phases succcssivcly :is the #fain passes through tbc blocks in advance, and means responsive in three different Ways ic thc hzjee phases of die i'ac'k current, Said means including c pim-ali@ of track reinys "fcscifiv fmck circuits. thc seveiai ieiajvs ci said track cit cuit being? dicreny responsive to varia'- tions ci? imse-'c the inici; cufrcn, iie ccnnccions ci" adjacent tack circuits being; ciaiivey reversed sc the; the curens im ajacent tac: circuits under simiar ccniitions are-1eieiveiy opposed in phase.

v1?.. En e block signal system, clocks having cui sectionsi track circuits for fzne sections, scui'ces of pciyphese currentci' the track circuits, a Piuality 0:5? track ifeieys for each crack cii'cuit :responsive 'tc change ci phase of the Heck cement, ccnacts ccntgcieci by the tack reiays of @sch bocf: fox controiing the current sunjgied ce che adjacent irack circuit cf the J"niece next in che rear, the contacts ccnrciied by the track relays of the iast-menicne irc-.ck circuit opeatingco shift the phase cf the cumen suppiied tc the track cifcui, nem in che Teef to three distinct pcsiicns, che track elays of che last-menticd track circuit @seing espcnsive in three di'erent combinations "cc che three i'een phases of the track cuircnt.

l2. En c bock signaling sys'frem, blocks heving cui; Section5-track circuits for the sections? sources of polyphase ciirrentfc the track circuias, a piumiiyof 'ack 11eays for each track circuit respcnsive cc change ci phase of the iack currect, ccntacts co'fced by che ltrackreleys ci' euch block foi' contrcilin the currezi suppiie to the adjacent tra circuit ci' the block next in the reci', the contacts controlled by A cent,

i3. cinte track reif i ci imc ase c'e'fen; atc? varying; c; fcc a iecic ciicmt, ami 'if-cr *Beijing* *he connections c n witness -whereof.' i ncve i'iexeimtc sec my hand this 5th day ci Auges@ w09, 

